Common use of Purchaser Obligations Clause in Contracts

Purchaser Obligations. The Parent agrees to take all action necessary to cause the Purchaser or the Surviving Corporation, as applicable, and, during the period between the Acceptance Time and the Effective Time, the Company, to perform all of its agreements, covenants and obligations under this Agreement. The Parent, the Purchaser and the Company have executed this Agreement as of the date set forth in the initial caption of this Agreement. Biogen Inc. By: /s/ ▇▇▇▇▇ ▇▇▇▇▇▇ Name: ▇▇▇▇▇ ▇▇▇▇▇▇ Title: Chief Financial Officer Aspen Purchaser Sub, Inc. By: /s/ ▇▇▇▇▇▇▇ ▇▇▇▇▇▇▇ Name: ▇▇▇▇▇▇▇ ▇▇▇▇▇▇▇ Title: Authorized Signatory Apellis Pharmaceuticals, Inc. By: /s/ ▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇ Name: ▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇ Title: President and Chief Executive Officer All terms defined in the Agreement and Plan of Merger (the “Agreement”) of which this Annex I is a part and used in this Annex I shall have the meanings assigned to such terms in the Agreement. Notwithstanding any other provisions of the Offer or the Agreement, the Purchaser shall not be required to accept for purchase or, subject to any applicable rules and regulations of the SEC, including Rule 14e-1(c) under the Exchange Act, to pay for any shares of Company Common Stock validly tendered pursuant to the Offer and not validly withdrawn prior to the Expiration Time if: (a) immediately prior to the Expiration Time, the number of shares of Company Common Stock validly tendered and not validly withdrawn (excluding shares tendered pursuant to guaranteed delivery procedures that have not yet been “received,” as such term is defined by Section 251(h)(6)(f) of the DGCL), together with any shares of Company Common Stock beneficially owned by the Parent or any Subsidiary of the Parent, does not equal at least one share more than fifty percent (50%) of all shares of Company Common Stock then outstanding (the “Minimum Condition”); (b) immediately prior to the Expiration Time, the waiting period (and any extension thereof) applicable to the Offer or the consummation of the Merger under the HSR Act shall not have either expired or been terminated; (c) any Governmental Entity of competent jurisdiction in any jurisdiction in which the Parent and its Subsidiaries or the Company and its Subsidiaries have business operations or assets, in each case, that are material to the Parent and its Subsidiaries, taken as a whole, or the Company and its Subsidiaries, taken as a whole, shall have issued, enacted, promulgated, enforced or entered any order, executive order, stay, decree, judgment, injunction (preliminary or permanent) or law that is in effect as of immediately prior to the Expiration Time which has the effect of prohibiting the consummation of the Offer or making the Merger illegal or otherwise prohibiting consummation of the Offer or the Merger; (d) (i) the representations and warranties of the Company contained in Section 3.7(a) of the Agreement are not true and correct in all respects as of immediately prior to the Expiration Time, as though made at and as of such time, (ii) the representations and warranties of the Company contained in the last sentence of Section 3.2(a) of the Agreement, the third, fourth and last sentences of Section 3.2(b) of the Agreement and the first sentence of Section 3.2(c) of the Agreement are not true and correct in all but de minimis respects as of immediately prior to the Expiration Time, as though made at and as of such time (except to the extent any such representation or warranty expressly relates to an earlier date or period, in which case as of such date or period), (iii) the representations and warranties set forth in the first Annex I – Page 1 sentence of Sections 3.1(a), 3.4(a), 3.4(b)(i) and 3.20 of the Agreement are not true and correct in all material respects as of immediately prior to the Expiration Time, as though made at and as of such time (except to the extent any such representation or warranty expressly relates to an earlier date or period, in which case as of such date or period), or (iv) all other representations and warranties of the Company contained in the Agreement are not true and correct as of immediately prior to the Expiration Time, as though made at and as of such time (except to the extent any such representation or warranty expressly relates to an earlier date or period, in which case as of such date or period), except, in the case of this clause (iv), where the failure of such representations or warranties to be true and correct (without giving effect to any limitation as to “materiality” or “Company Material Adverse Effect” set forth in such representations and warranties) would not reasonably be expected to have a Company Material Adverse Effect; (e) the Company shall have failed to perform in all material respects its covenants and obligations required to be performed or complied with by it under the Agreement at or prior to the Expiration Time; (f) the Parent shall not have received a certificate, dated as of the date on which the Acceptance Time occurs, signed by an executive officer of the Company certifying that the conditions set forth in clauses (d) and (e) of this Annex I do not exist as of immediately prior to the Expiration Time; or (g) the Agreement shall have been validly terminated in accordance with Article VIII of the Agreement. Annex I – Page 2 THIS CONTINGENT VALUE RIGHTS AGREEMENT, dated as of [•] (this “Agreement”), is entered into by and among Biogen Inc., a Delaware corporation (the “Parent”), Apellis Pharmaceuticals, Inc., a Delaware corporation (together with any successor thereto, the “Company”), and [•], a [•], as Rights Agent.

Purchaser Obligations. The Parent agrees to take all action necessary to cause the Purchaser or the Surviving Corporation, as applicable, and, during the period between the Acceptance Time and the Effective Time, the Company, to perform all of its agreements, covenants and obligations under this Agreement. The Parent1.1 At Closing, the Purchaser and the Company have executed this Agreement as of the date set forth in the initial caption of this Agreement. Biogen Inc. By: /s/ ▇▇▇▇▇ ▇▇▇▇▇▇ Name: ▇▇▇▇▇ ▇▇▇▇▇▇ Title: Chief Financial Officer Aspen Purchaser Sub, Inc. By: /s/ ▇▇▇▇▇▇▇ ▇▇▇▇▇▇▇ Name: ▇▇▇▇▇▇▇ ▇▇▇▇▇▇▇ Title: Authorized Signatory Apellis Pharmaceuticals, Inc. By: /s/ ▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇ Name: ▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇ Title: President and Chief Executive Officer All terms defined in the Agreement and Plan of Merger (the “Agreement”) of which this Annex I is a part and used in this Annex I shall have the meanings assigned to such terms in the Agreement. Notwithstanding any other provisions of the Offer or the Agreement, the Purchaser shall not be required to accept for purchase or, subject to any applicable rules and regulations of the SEC, including Rule 14e-1(c) under the Exchange Act, to pay for any shares of Company Common Stock validly tendered pursuant to the Offer and not validly withdrawn prior to the Expiration Time ifshall: (a) immediately prior deliver (or ensure that there is delivered to the Expiration Time, Sellers’ Representative) an officer’s certificate confirming that the number board of shares of Company Common Stock validly tendered and not validly withdrawn (excluding shares tendered pursuant to guaranteed delivery procedures that have not yet been “received,” as such term is defined by Section 251(h)(6)(f) directors of the DGCL), together with any shares Purchaser has authorised the execution of Company Common Stock beneficially owned and the performance by the Parent or any Subsidiary Purchaser, and its subsidiaries, from time to time, of its and their obligations under this Deed and each of the Parent, does not equal at least one share more than fifty percent (50%) of all shares of Company Common Stock then outstanding (the “Minimum Condition”)Transaction Documents to be executed by it; (b) immediately prior to the Expiration Time, the waiting period (and any extension thereof) applicable to the Offer or the consummation deliver copies of the Merger under Evercore LLP Agreement duly executed by the HSR Act shall not have either expired or been terminatedparties thereto; (c) any Governmental Entity procure the execution of competent jurisdiction in any jurisdiction in which all documentation (including the Parent and its Subsidiaries or passing of relevant resolutions) of the Company and its Subsidiaries have business operations or assets, in each case, that are material to Evercore LLP approving the Parent and its Subsidiaries, taken as a whole, or appointment of all of the Company and its Subsidiaries, taken as a whole, shall have issued, enacted, promulgated, enforced or entered any order, executive order, stay, decree, judgment, injunction (preliminary or permanent) or law that is in effect as members of the Lexicon LLP immediately prior to the Expiration Time which has the effect of prohibiting the consummation Closing as members of the Offer or making the Merger illegal or otherwise prohibiting consummation Evercore LLP with effect from Closing, including, without limitation, a duly executed Evercore LLP Schedule of the Offer or the MergerTerms in respect of each such member; (d) (i) the representations and warranties procure delivery of an Evercore L.P. indemnity pursuant to clause 28 of the Company contained in Section 3.7(a) of the Agreement are not true and correct in all respects as of immediately prior to the Expiration Time, as though made at and as of such time, (ii) the representations and warranties of the Company contained in the last sentence of Section 3.2(a) of the Evercore LLP Agreement, the third, fourth and last sentences of Section 3.2(b) of the Agreement and the first sentence of Section 3.2(c) of the Agreement are not true and correct in all but de minimis respects as of immediately prior to the Expiration Time, as though made at and as of such time (except to the extent any such representation or warranty expressly relates to an earlier date or period, in which case as of such date or period), (iii) the representations and warranties set forth in the first Annex I – Page 1 sentence of Sections 3.1(a), 3.4(a), 3.4(b)(i) and 3.20 of the Agreement are not true and correct in all material respects as of immediately prior to the Expiration Time, as though made at and as of such time (except to the extent any such representation or warranty expressly relates to an earlier date or period, in which case as of such date or period), or (iv) all other representations and warranties of the Company contained in the Agreement are not true and correct as of immediately prior to the Expiration Time, as though made at and as of such time (except to the extent any such representation or warranty expressly relates to an earlier date or period, in which case as of such date or period), except, in the case of this clause (iv), where the failure of such representations or warranties to be true and correct (without giving effect to any limitation as to “materiality” or “Company Material Adverse Effect” set forth in such representations and warranties) would not reasonably be expected to have a Company Material Adverse Effect; (e) pay by electronic funds transfer the Company shall have failed Cash Consideration due to perform in all material respects its covenants and obligations required to be performed or complied with by it under of the Agreement at or prior Sellers taken as a whole to the Expiration TimeSellers’ Bank Account; (f) the Parent shall not have received a certificate, dated as pay by electronic funds transfer all of the date on which amounts due to the Acceptance Time occurs, signed by an executive officer of the Company certifying that the conditions set forth in clauses (d) and (e) Loan Note Holders pursuant to clause 5.4 of this Annex I do not exist as of immediately prior Deed to the Expiration Time; orLoan Note Holders’ Bank Account; (g) issue to each Seller the Agreement shall have been validly terminated number of Unrestricted Shares set out opposite the name of such Seller in column 4 of Part A of the Consideration Memo (in the case of a Type A Seller) or column 4 of Part B of the Consideration Memo (in the case of a Type B Seller) to which such Seller is entitled; (h) issue to the Restriction Agent the number of Transfer Restricted Shares set out opposite the name of each Seller in column 5 of Part A of the Consideration Memo (in the case of a Type A Seller) or column 5 of Part B of the Consideration Memo (in the case of a Type B Seller) to which each Seller is entitled under the terms of Schedule 10 (such issuance to be made subject to the terms set out in Schedule 10); (i) implement the Retention Awards in accordance with Article VIII of the Agreement. Annex I – Page 2 THIS CONTINGENT VALUE RIGHTS AGREEMENT, dated as of [•] (this “Agreement”), is entered into by and among Biogen Inc., a Delaware corporation (the “Parent”), Apellis Pharmaceuticals, Inc., a Delaware corporation (together with any successor thereto, the “Company”), and [•], a [•], as Rights Agentterms set out in Schedule 2.

Purchaser Obligations. The Parent agrees to take all action necessary to cause the Purchaser or the Surviving Corporation, as applicable, and, during the period between the Acceptance Time and the Effective Time, the Company, to perform all of its agreements, covenants and obligations under this Agreement. The Parent, the Purchaser and the Company have executed this Agreement as of the date set forth in the initial caption of this Agreement. Biogen Inc. By: /s/ ▇▇▇▇▇ ▇▇▇▇▇▇ Name: ▇▇▇▇▇ ▇▇▇▇▇▇ Title: Chief Financial Officer Aspen Purchaser Sub, Inc. By: /s/ ▇▇▇▇▇▇▇ ▇▇▇▇▇▇▇ Name: ▇▇▇▇▇▇▇ ▇▇▇▇▇▇▇ Title: Authorized Signatory Apellis Pharmaceuticals, Inc. By: /s/ ▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇ Name: ▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇ Title: President and Chief Executive Officer All terms defined in the Agreement and Plan of Merger (the “Agreement”) of which this Annex I is a part and used in this Annex I shall have the meanings assigned to such terms in the Agreement. Notwithstanding any other provisions of the Offer or the Agreement, the Purchaser shall not be required to accept for purchase or, subject to any applicable rules and regulations of the SEC, including Rule 14e-1(c) under the Exchange Act, to pay for any shares of Company Common Stock validly tendered pursuant to the Offer and not validly withdrawn prior to the Expiration Time if: (a) immediately prior Each Purchaser hereby covenants with the Company not to the Expiration Time, the number of shares of Company Common Stock validly tendered and not validly withdrawn (excluding shares tendered pursuant to guaranteed delivery procedures that have not yet been “received,” as such term is defined by Section 251(h)(6)(f) make any sale of the DGCL), together Registrable Shares without complying with any shares of Company Common Stock beneficially owned by the Parent or any Subsidiary of the Parent, does not equal at least one share more than fifty percent (50%) of all shares of Company Common Stock then outstanding (the “Minimum Condition”);Section 8.3. (b) immediately prior Each Purchaser agrees that, upon receipt of any notice from the Company of the happening of any event requiring the preparation of a supplement or amendment to a prospectus forming a part of the Registration Statement so that, as thereafter delivered to the Expiration TimePurchaser, such prospectus shall not contain an untrue statement of a material fact or omit to state any material fact required to be stated therein or necessary to make the waiting period (and any extension thereof) applicable statements therein not misleading, each Purchaser shall forthwith discontinue disposition of Registrable Shares pursuant to the Offer or the consummation Registration Statement and prospectus contemplated by Section 7.2 until its receipt of copies of the Merger under supplemented or amended prospectus from the HSR Act Company and, if so directed by the Company, each Purchaser shall not have either expired or been terminated;deliver to the Company all copies, other than permanent file copies then in such Purchaser’s possession, of the prospectus covering such Registrable Shares currently in such Purchaser’s possession at the time of receipt of such notice. (c) Each Purchaser shall suspend, upon request of the Company, any Governmental Entity disposition of competent jurisdiction Registrable Shares pursuant the Registration Statement and prospectus contemplated by Section 7.2 during any period, so long as the aggregate number of days during which such disposition is suspended in any jurisdiction one six (6) month period does not exceed forty-five (45) days, (i) that the Company requires in connection with a primary underwritten offering of equity securities; or (ii) if the Company determines in good faith that offers and sales pursuant thereto should not be made by reason of the presence of material undisclosed circumstances or developments with respect to which the Parent and its Subsidiaries disclosure that would be required in such a prospectus is premature or would have an adverse effect on the Company; provided that the Company and its Subsidiaries have business operations will amend or assetssupplement, in each case, that are material to the Parent and its Subsidiariesextent necessary, taken as a wholethe Registration Statement, or at the Company and its Subsidiaries, taken as a whole, shall have issued, enacted, promulgated, enforced or entered any order, executive order, stay, decree, judgment, injunction (preliminary or permanent) or law that is in effect as end of immediately prior such period to allow the Purchaser to dispose of the Registrable Shares pursuant to the Expiration Time which has the effect of prohibiting the consummation of the Offer or making the Merger illegal or otherwise prohibiting consummation of the Offer or the Merger;Registration Statement. (d) (i) As a condition to the representations and warranties inclusion of its Registrable Shares, each Purchaser shall furnish to the Company contained in Section 3.7(a) of such information regarding such Purchaser and the Agreement are not true and correct in all respects distribution proposed by such Purchaser as of immediately prior to the Expiration Time, as though made at and as of such time, (ii) the representations and warranties of the Company contained may request in writing, including completing the last sentence of Section 3.2(a) of the Agreement, the third, fourth and last sentences of Section 3.2(b) of the Agreement and the first sentence of Section 3.2(c) of the Agreement are not true and correct in all but de minimis respects Registration Statement Questionnaire attached hereto as of immediately prior to the Expiration Time, as though made at and as of such time (except to the extent any such representation or warranty expressly relates to an earlier date or period, in which case as of such date or period), (iii) the representations and warranties set forth in the first Annex I – Page 1 sentence of Sections 3.1(a), 3.4(a), 3.4(b)(i) and 3.20 of the Agreement are not true and correct in all material respects as of immediately prior to the Expiration Time, as though made at and as of such time (except to the extent any such representation or warranty expressly relates to an earlier date or period, in which case as of such date or period), or (iv) all other representations and warranties of the Company contained in the Agreement are not true and correct as of immediately prior to the Expiration Time, as though made at and as of such time (except to the extent any such representation or warranty expressly relates to an earlier date or period, in which case as of such date or period), except, in the case of this clause (iv), where the failure of such representations or warranties to be true and correct (without giving effect to any limitation as to “materiality” or “Company Material Adverse Effect” set forth in such representations and warranties) would not reasonably be expected to have a Company Material Adverse Effect; (e) the Company shall have failed to perform in all material respects its covenants and obligations required to be performed or complied with by it under the Agreement at or prior to the Expiration Time; (f) the Parent shall not have received a certificate, dated as of the date on which the Acceptance Time occurs, signed by an executive officer of the Company certifying that the conditions set forth in clauses (d) and (e) of this Annex I do not exist as of immediately prior to the Expiration Time; or (g) the Agreement shall have been validly terminated in accordance with Article VIII of the Agreement. Annex I – Page 2 THIS CONTINGENT VALUE RIGHTS AGREEMENT, dated as of [•] (this “Agreement”), is entered into by and among Biogen Inc., a Delaware corporation (the “Parent”), Apellis Pharmaceuticals, Inc., a Delaware corporation (together with any successor thereto, the “Company”), and [•], a [•], as Rights Agent.Exhibit C.

Purchaser Obligations. (a) The Parent Purchaser agrees that, upon receipt of any notice from the Company of the happening of any event requiring the preparation of a supplement or amendment to take all action a prospectus relating to Registrable Shares so that, as thereafter delivered to the Purchaser, such prospectus shall not contain an untrue statement of a material fact or omit to state any material fact required to be stated therein or necessary to cause make the statements therein not misleading, the Purchaser will forthwith discontinue disposition of Registrable Shares pursuant to a registration statement and prospectus contemplated by Section 8.1. until its receipt of copies of the supplemented or amended prospectus from the Surviving Corporation, as applicable, Company and, during the period between the Acceptance Time and the Effective Time, if so directed by the Company, the Purchaser shall deliver to perform the Company all copies, other than permanent file copies then in the Purchaser’s possession, of the prospectus covering such Registrable Shares current at the time of receipt of such notice. (b) The Purchaser shall suspend, upon request of the Company, any disposition of Registrable Shares pursuant to any registration statement and prospectus contemplated by Section 8.1. during the occurrence or existence of any pending corporate development with respect to the Company that the Board of Directors of the Company believes in good faith may be material and that, in the determination of the Board of Directors of the Company, makes it not in the best interest of the Company to allow continued availability of a registration statement or prospectus. (c) As a condition to the inclusion of its agreementsRegistrable Shares, covenants and obligations under this Agreement. The Parent, the Purchaser shall furnish to the Company such information regarding the Purchaser and the distribution proposed by the Purchaser as the Company have executed this Agreement as of the date set forth may reasonably request in writing, including completing a registration statement questionnaire in the initial caption of this Agreement. Biogen Inc. By: /s/ ▇▇▇▇▇ ▇▇▇▇▇▇ Name: ▇▇▇▇▇ ▇▇▇▇▇▇ Title: Chief Financial Officer Aspen Purchaser Subform provided by the Company, Inc. By: /s/ ▇▇▇▇▇▇▇ ▇▇▇▇▇▇▇ Name: ▇▇▇▇▇▇▇ ▇▇▇▇▇▇▇ Title: Authorized Signatory Apellis Pharmaceuticals, Inc. By: /s/ ▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇ Name: ▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇ Title: President and Chief Executive Officer All terms defined or as shall be required in the Agreement and Plan of Merger (the “Agreement”) of which this Annex I is a part and used connection with any registration referred to in this Annex I shall have the meanings assigned to such terms in the Agreement. Notwithstanding any other provisions of the Offer or the Agreement, the Purchaser shall not be required to accept for purchase or, subject to any applicable rules and regulations of the SEC, including Rule 14e-1(c) under the Exchange Act, to pay for any shares of Company Common Stock validly tendered pursuant to the Offer and not validly withdrawn prior to the Expiration Time if: (a) immediately prior to the Expiration Time, the number of shares of Company Common Stock validly tendered and not validly withdrawn (excluding shares tendered pursuant to guaranteed delivery procedures that have not yet been “received,” as such term is defined by Section 251(h)(6)(f) of the DGCL), together with any shares of Company Common Stock beneficially owned by the Parent or any Subsidiary of the Parent, does not equal at least one share more than fifty percent (50%) of all shares of Company Common Stock then outstanding (the “Minimum Condition”); (b) immediately prior to the Expiration Time, the waiting period (and any extension thereof) applicable to the Offer or the consummation of the Merger under the HSR Act shall not have either expired or been terminated; (c) any Governmental Entity of competent jurisdiction in any jurisdiction in which the Parent and its Subsidiaries or the Company and its Subsidiaries have business operations or assets, in each case, that are material to the Parent and its Subsidiaries, taken as a whole, or the Company and its Subsidiaries, taken as a whole, shall have issued, enacted, promulgated, enforced or entered any order, executive order, stay, decree, judgment, injunction (preliminary or permanent) or law that is in effect as of immediately prior to the Expiration Time which has the effect of prohibiting the consummation of the Offer or making the Merger illegal or otherwise prohibiting consummation of the Offer or the Merger;8. (d) The Purchaser hereby covenants with the Company (i) the representations and warranties not to make any sale of the Company contained in Section 3.7(a) of Registrable Shares without effectively causing the Agreement are not true prospectus delivery requirements under the Securities Act to be satisfied, and correct in all respects as of immediately prior to the Expiration Time, as though made at and as of such time, (ii) if such Registrable Shares are to be sold by any method or in any transaction other than on a national securities exchange or in the representations and warranties over-the-counter market, in privately negotiated transactions, or in a combination of such methods, to notify the Company contained in the last sentence of Section 3.2(aat least three (3) of the Agreement, the third, fourth and last sentences of Section 3.2(b) of the Agreement and the first sentence of Section 3.2(c) of the Agreement are not true and correct in all but de minimis respects as of immediately business days prior to the Expiration Time, as though made at and as of such time (except to the extent any such representation or warranty expressly relates to an earlier date or period, in which case as of such date or period), (iii) the representations and warranties set forth in the first Annex I – Page 1 sentence of Sections 3.1(a), 3.4(a), 3.4(b)(i) and 3.20 of the Agreement are not true and correct in all material respects as of immediately prior to the Expiration Time, as though made at and as of such time (except to the extent any such representation or warranty expressly relates to an earlier date or period, in which case as of such date or period), or (iv) all other representations and warranties of the Company contained in the Agreement are not true and correct as of immediately prior to the Expiration Time, as though made at and as of such time (except to the extent any such representation or warranty expressly relates to an earlier date or period, in which case as of such date or period), except, in the case of this clause (iv), where the failure of such representations or warranties to be true and correct (without giving effect to any limitation as to “materiality” or “Company Material Adverse Effect” set forth in such representations and warranties) would not reasonably be expected to have a Company Material Adverse Effect; (e) the Company shall have failed to perform in all material respects its covenants and obligations required to be performed or complied with by it under the Agreement at or prior to the Expiration Time; (f) the Parent shall not have received a certificate, dated as of the date on which the Acceptance Time occurs, signed by an executive officer of the Company certifying that the conditions set forth in clauses (d) and Purchaser first offers to sell any such Registrable Shares. (e) The Purchaser agrees not to take any action with respect to any distribution deemed to be made pursuant to a registration statement which would constitute a violation of this Annex I do not exist as of immediately prior to Regulation M under the Expiration Time; orExchange Act or any other applicable rule, regulation or law. (gf) At the Agreement shall have been validly terminated in accordance with Article VIII end of the Agreement. Annex I – Page 2 THIS CONTINGENT VALUE RIGHTS AGREEMENT, dated as Registration Period the Purchaser shall discontinue sales of [•] (this “Agreement”), is entered into shares pursuant to any registration statement upon receipt of notice from the Company of its intention to remove from registration the shares covered by and among Biogen Inc., a Delaware corporation (the “Parent”), Apellis Pharmaceuticals, Inc., a Delaware corporation (together with any successor thereto, the “Company”)such registration statement which remain unsold, and [•], a [•], as Rights Agentthe Purchaser shall notify the Company of the number of shares registered which remain unsold immediately upon receipt of such notice from the Company.

Purchaser Obligations. The Parent agrees to take all action necessary to cause the Purchaser or the Surviving Corporation, as applicable, and, during the period between the Acceptance Time and the Effective Time, the Company, to perform all of its agreements, covenants and obligations under this Agreement. The Parent, the Purchaser and the Company have executed this Agreement as of the date set forth in the initial caption of this Agreement. Biogen Inc. By: /s/ ▇▇▇▇▇ ▇▇▇▇▇▇ Name: ▇▇▇▇▇ ▇▇▇▇▇▇ Title: Chief Financial Officer Aspen Purchaser Sub, Inc. By: /s/ ▇▇▇▇▇▇▇ ▇▇▇▇▇▇▇ Name: ▇▇▇▇▇▇▇ ▇▇▇▇▇▇▇ Title: Authorized Signatory Apellis Pharmaceuticals, Inc. By: /s/ ▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇ Name: ▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇ Title: President and Chief Executive Officer All terms defined in the Agreement and Plan of Merger (the “Agreement”) of which this Annex I is a part and used in this Annex I shall have the meanings assigned to such terms in the Agreement. Notwithstanding any other provisions of the Offer or the Agreement, the Purchaser shall not be required to accept for purchase or, subject to any applicable rules and regulations of the SEC, including Rule 14e-1(c) under the Exchange Act, to pay for any shares of Company Common Stock validly tendered pursuant to the Offer and not validly withdrawn prior to the Expiration Time if:​ (a) immediately At least five (5) Business Days prior to the Expiration Timefirst anticipated filing date of a Registration Statement, the number Company shall notify the Purchaser in writing of shares the information the Company requires from the Purchaser if the Purchaser elects to have any of the Purchaser’s Registrable Securities included in such Registration Statement. It shall be a condition precedent to the obligations of the Company Common Stock validly tendered and not validly withdrawn (excluding shares tendered to complete the registration pursuant to guaranteed delivery procedures this Agreement with respect to the Registrable Securities that have not yet been “received,” as (i) the Purchaser furnish to the Company such term is defined information regarding itself, the Registrable Securities held by Section 251(h)(6)(f) it and the intended method of disposition of the DGCL), together with any shares of Company Common Stock beneficially owned Registrable Securities held by it as shall be reasonably required to effect the Parent or any Subsidiary effectiveness of the Parentregistration of such Registrable Securities, does not equal at least one share more than fifty percent and (50%ii) of all shares of the Purchaser execute such documents in connection with such registration as the Company Common Stock then outstanding (the “Minimum Condition”);may reasonably request. ​ (b) immediately prior The Purchaser covenants and agrees by its acquisition of such Registrable Securities that (i) it will not sell any Registrable Securities under the Registration Statement until it has ​ 8 ​ ​ ​ ​ ​ received copies of the Prospectus as then amended or supplemented as contemplated in Section 3.1(g) and notice from the Company that such Registration Statement and any post-effective amendments thereto have become effective as contemplated by Section 3.1(c)(i)–(ii) and its officers, directors or Affiliates, if any, will comply with the prospectus delivery requirements of the Securities Act as applicable to them in connection with sales of Registrable Securities pursuant to the Expiration Time, the waiting period (and any extension thereof) applicable to the Offer or the consummation of the Merger under the HSR Act shall not have either expired or been terminated;Registration Statement. ​ (c) any Governmental Entity Upon receipt of competent jurisdiction in any jurisdiction in which the Parent and its Subsidiaries or a notice from the Company and its Subsidiaries have business operations or assets, of the occurrence of any event of the kind described in each case, that are material to the Parent and its Subsidiaries, taken as a whole, or the Company and its Subsidiaries, taken as a whole, shall have issued, enacted, promulgated, enforced or entered any order, executive order, stay, decree, judgment, injunction (preliminary or permanentSection 3.1(c)(ii)–(v) or law that is in effect as Section 3.1(l), the Purchaser will forthwith discontinue disposition of immediately prior to such Registrable Securities under the Expiration Time which has Registration Statement until the effect of prohibiting the consummation Purchaser’s receipt of the Offer or making the Merger illegal or otherwise prohibiting consummation copies of the Offer or the Merger; (d) (i) the representations and warranties of the Company contained in supplemented Prospectus and/or amended Registration Statement contemplated by Section 3.7(a) of the Agreement are not true and correct in all respects as of immediately prior to the Expiration Time, as though made at and as of such time, (ii) the representations and warranties of the Company contained in the last sentence of Section 3.2(a) of the Agreement, the third, fourth and last sentences of Section 3.2(b) of the Agreement and the first sentence of Section 3.2(c) of the Agreement are not true and correct in all but de minimis respects as of immediately prior to the Expiration Time, as though made at and as of such time (except to the extent any such representation or warranty expressly relates to an earlier date or period, in which case as of such date or period), (iii) the representations and warranties set forth in the first Annex I – Page 1 sentence of Sections 3.1(a), 3.4(a), 3.4(b)(i) and 3.20 of the Agreement are not true and correct in all material respects as of immediately prior to the Expiration Time, as though made at and as of such time (except to the extent any such representation or warranty expressly relates to an earlier date or period, in which case as of such date or period3.1(i), or (iv) all other representations and warranties until it is advised in writing by the Company that the use of the Company contained in the Agreement are not true and correct as of immediately prior to the Expiration Timeapplicable Prospectus may be resumed, as though made at and as of such time (except to the extent any such representation or warranty expressly relates to an earlier date or periodand, in which case as either case, has received copies of such date any additional or period), except, in the case of this clause (iv), where the failure of such representations supplemental filings that are incorporated or warranties deemed to be true and correct (without giving effect to any limitation as to “materiality” or “Company Material Adverse Effect” set forth incorporated by reference in such representations and warranties) would not reasonably be expected to have a Company Material Adverse Effect; (e) the Company shall have failed to perform in all material respects its covenants and obligations required to be performed Prospectus or complied with by it under the Agreement at or prior to the Expiration Time; (f) the Parent shall not have received a certificate, dated as of the date on which the Acceptance Time occurs, signed by an executive officer of the Company certifying that the conditions set forth in clauses (d) and (e) of this Annex I do not exist as of immediately prior to the Expiration Time; or (g) the Agreement shall have been validly terminated in accordance with Article VIII of the AgreementRegistration Statement. Annex I – Page 2 THIS CONTINGENT VALUE RIGHTS AGREEMENT, dated as of [•] (this “Agreement”), is entered into by and among Biogen Inc., a Delaware corporation (the “Parent”), Apellis Pharmaceuticals, Inc., a Delaware corporation (together with any successor thereto, the “Company”), and [•], a [•], as Rights Agent.​

Purchaser Obligations. The Parent agrees to take all action necessary to cause the Purchaser or the Surviving Corporation, as applicable, and, during the period between the Acceptance Time and the Effective Time, the Company, to perform all of its agreements, covenants and obligations under this Agreement. The Parent, the Purchaser and the Company have executed this Agreement as of the date set forth in the initial caption of this Agreement. Biogen Inc. By: /s/ ▇▇▇▇▇ ▇▇▇▇▇▇ Name: ▇▇▇▇▇ ▇▇▇▇▇▇ Title: Chief Financial Officer Aspen Purchaser Sub, Inc. By: /s/ ▇▇▇▇▇▇▇ ▇▇▇▇▇▇▇ Name: ▇▇▇▇▇▇▇ ▇▇▇▇▇▇▇ Title: Authorized Signatory Apellis Pharmaceuticals, Inc. By: /s/ ▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇ Name: ▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇ Title: President and Chief Executive Officer All terms defined in the Agreement and Plan of Merger (the “Agreement”a) of which this Annex I is a part and used in this Annex I shall have the meanings assigned to such terms in the Agreement. Notwithstanding any other provisions of the Offer or the Agreement, the Purchaser shall not be required to accept for purchase or, subject to any applicable rules and regulations of the SEC, including Rule 14e-1(cAt least five (5) under the Exchange Act, to pay for any shares of Company Common Stock validly tendered pursuant to the Offer and not validly withdrawn Business Days prior to the Expiration Time if: (a) immediately prior first anticipated filing date of a Registration Statement, the Company shall notify the Purchaser in writing of the information the Company requires from the Purchaser if the Purchaser elects to have any of the Purchaser’s Registrable Securities included in such Registration Statement. It shall be a condition precedent to the Expiration Timeobligations of the Company to complete the registration pursuant to this Agreement with respect to the Registrable Securities that (i) the Purchaser furnish to the Company such information regarding itself, the number Registrable Securities held by it and the intended method of shares of Company Common Stock validly tendered and not validly withdrawn (excluding shares tendered pursuant to guaranteed delivery procedures that have not yet been “received,” as such term is defined by Section 251(h)(6)(f) disposition of the DGCL), together with any shares of Company Common Stock beneficially owned Registrable Securities held by it as shall be reasonably required to effect the Parent or any Subsidiary effectiveness of the Parentregistration of such Registrable Securities, does not equal at least one share more than fifty percent and (50%ii) of all shares of the Purchaser execute such documents in connection with such registration as the Company Common Stock then outstanding (the “Minimum Condition”);may reasonably request. (b) immediately prior The Purchaser covenants and agrees by its acquisition of such Registrable Securities that (i) it will not sell any Registrable Securities under the Registration Statement until it has received copies of the Prospectus as then amended or supplemented as contemplated in Section 3.1(g) and notice from the Company that such Registration Statement and any post-effective amendments thereto have become effective as contemplated by Section 3.1(c)(i)–(ii) and its officers, directors or Affiliates, if any, will comply with the prospectus delivery requirements of the Securities Act as applicable to them in connection with sales of Registrable Securities pursuant to the Expiration Time, the waiting period (and any extension thereof) applicable to the Offer or the consummation of the Merger under the HSR Act shall not have either expired or been terminated;Registration Statement. (c) any Governmental Entity Upon receipt of competent jurisdiction in any jurisdiction in which the Parent and its Subsidiaries or a notice from the Company and its Subsidiaries have business operations or assets, of the occurrence of any event of the kind described in each case, that are material to the Parent and its Subsidiaries, taken as a whole, or the Company and its Subsidiaries, taken as a whole, shall have issued, enacted, promulgated, enforced or entered any order, executive order, stay, decree, judgment, injunction (preliminary or permanentSection 3.1(c)(ii)–(v) or law that is in effect as Section 3.1(l), the Purchaser will forthwith discontinue disposition of immediately prior to such Registrable Securities under the Expiration Time which has Registration Statement until the effect of prohibiting the consummation Purchaser’s receipt of the Offer or making the Merger illegal or otherwise prohibiting consummation copies of the Offer or the Merger; (d) (i) the representations and warranties of the Company contained in supplemented Prospectus and/or amended Registration Statement contemplated by Section 3.7(a) of the Agreement are not true and correct in all respects as of immediately prior to the Expiration Time, as though made at and as of such time, (ii) the representations and warranties of the Company contained in the last sentence of Section 3.2(a) of the Agreement, the third, fourth and last sentences of Section 3.2(b) of the Agreement and the first sentence of Section 3.2(c) of the Agreement are not true and correct in all but de minimis respects as of immediately prior to the Expiration Time, as though made at and as of such time (except to the extent any such representation or warranty expressly relates to an earlier date or period, in which case as of such date or period), (iii) the representations and warranties set forth in the first Annex I – Page 1 sentence of Sections 3.1(a), 3.4(a), 3.4(b)(i) and 3.20 of the Agreement are not true and correct in all material respects as of immediately prior to the Expiration Time, as though made at and as of such time (except to the extent any such representation or warranty expressly relates to an earlier date or period, in which case as of such date or period3.1(i), or (iv) all other representations and warranties until it is advised in writing by the Company that the use of the Company contained in the Agreement are not true and correct as of immediately prior to the Expiration Timeapplicable Prospectus may be resumed, as though made at and as of such time (except to the extent any such representation or warranty expressly relates to an earlier date or periodand, in which case as either case, has received copies of such date any additional or period), except, in the case of this clause (iv), where the failure of such representations supplemental filings that are incorporated or warranties deemed to be true and correct (without giving effect to any limitation as to “materiality” or “Company Material Adverse Effect” set forth incorporated by reference in such representations and warranties) would not reasonably be expected to have a Company Material Adverse Effect; (e) the Company shall have failed to perform in all material respects its covenants and obligations required to be performed Prospectus or complied with by it under the Agreement at or prior to the Expiration Time; (f) the Parent shall not have received a certificate, dated as of the date on which the Acceptance Time occurs, signed by an executive officer of the Company certifying that the conditions set forth in clauses (d) and (e) of this Annex I do not exist as of immediately prior to the Expiration Time; or (g) the Agreement shall have been validly terminated in accordance with Article VIII of the Agreement. Annex I – Page 2 THIS CONTINGENT VALUE RIGHTS AGREEMENT, dated as of [•] (this “Agreement”), is entered into by and among Biogen Inc., a Delaware corporation (the “Parent”), Apellis Pharmaceuticals, Inc., a Delaware corporation (together with any successor thereto, the “Company”), and [•], a [•], as Rights AgentRegistration Statement.

Purchaser Obligations. The Parent agrees to take all action necessary to cause Parties acknowledge, understand and agree that, after the Purchaser or the Surviving CorporationClosing, as applicable, and, during the period between the Acceptance Time and the Effective Time, the Company, to perform all of its agreements, covenants and obligations under this Agreement. The Parent, the Purchaser and its Affiliates (i) have complete control and sole and absolute discretion with respect to decisions concerning the Company have executed this Agreement as operations of the date set forth in the initial caption business and assets of this Agreement. Biogen Inc. By: /s/ ▇▇▇▇▇ ▇▇▇▇▇▇ Name: ▇▇▇▇▇ ▇▇▇▇▇▇ Title: Chief Financial Officer Aspen Purchaser Sub, Inc. By: /s/ ▇▇▇▇▇▇▇ ▇▇▇▇▇▇▇ Name: ▇▇▇▇▇▇▇ ▇▇▇▇▇▇▇ Title: Authorized Signatory Apellis Pharmaceuticals, Inc. By: /s/ ▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇ Name: ▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇ Title: President and Chief Executive Officer All terms defined in the Agreement and Plan of Merger (the “Agreement”) of which this Annex I is a part and used in this Annex I shall have the meanings assigned to such terms in the Agreement. Notwithstanding any other provisions of the Offer or the Agreement, the Purchaser shall not be required to accept for purchase or, subject to any applicable rules and regulations of the SEC, including Rule 14e-1(c) under the Exchange Act, to pay for any shares of Company Common Stock validly tendered pursuant to the Offer and not validly withdrawn prior to the Expiration Time if: (a) immediately prior to the Expiration Time, the number of shares of Company Common Stock validly tendered and not validly withdrawn (excluding shares tendered pursuant to guaranteed delivery procedures that have not yet been “received,” as such term is defined by Section 251(h)(6)(f) of the DGCL), together with any shares of Company Common Stock beneficially owned by the Parent or any Subsidiary of the Parent, does not equal at least one share more than fifty percent (50%) of all shares of Company Common Stock then outstanding (the “Minimum Condition”); (b) immediately prior to the Expiration Time, the waiting period (and any extension thereof) applicable to the Offer or the consummation of the Merger under the HSR Act shall not have either expired or been terminated; (c) any Governmental Entity of competent jurisdiction in any jurisdiction in which the Parent and its Subsidiaries or the Company and its Subsidiaries have business operations and (ii) are only required to take actions in connection with Company and its Subsidiaries that Purchaser and its Affiliates believe to be in the best interests of Purchaser and, as applicable, its Affiliates, and do not owe any duties to the Main Sellers by virtue of this Section 1.5 (other than to make the 2016 Conditional Deferred Payment or assetsthe 2017 Condition Deferred Payment when earned); provided, however, that (A) Purchaser and its Affiliates shall use commercially reasonable efforts and resources to achieve the milestones mentioned above, (B) Purchaser shall not cause Company to take or fail to take any action, and Company shall not intentionally take or fail to take any action, in each caseany such event with the purpose of frustrating the ability of Main Sellers to receive the maximum permissible 2016 Conditional Deferred Payment and 2017 Condition Deferred Payment and (C) Purchaser shall operate the Company in the ordinary course of business and on a basis consistent with past practice, that are except as set forth in Exhibit C hereto and shall not sell, transfer, assign or otherwise dispose of (directly or indirectly) material assets outside of the ordinary course of business used primarily in Company’s business to a Person who is not an Affiliate of Purchaser. In the event Purchaser shall (1) sell, transfer, assign or otherwise dispose of (directly or indirectly) all or substantially all of the business assets used primarily in Company’s business to a Person who is not an Affiliate of Purchaser, or (2) consummate any consolidation, merger, combination or other similar transaction in which the voting control of the surviving entity is transferred to a Person who is not an Affiliate of Purchaser, (3) sell, transfer, assign or otherwise dispose of (directly or indirectly) voting equity interests in Company if as a result of such sale, transfer, assignment or disposition voting control of the surviving entity is transferred to a Person who is not an Affiliate of Purchaser, or (4) terminate the Chief Executive Officer of the Company, other than for Cause, the obligations of Purchaser hereunder shall be accelerated and the Main Sellers shall immediately be entitled to and promptly receive the maximum 2016 Conditional Deferred Payment and 2017 Condition Deferred Payment pursuant to this Section 1.5 (to the Parent and its Subsidiariesextent not already earned, taken as a wholepaid or not earned). Subject to Section 6.7, or Purchaser shall keep Sellers’ Representatives reasonably informed of any change in the Company and its Subsidiaries, taken as a whole, shall have issued, enacted, promulgated, enforced or entered any order, executive order, stay, decree, judgment, injunction (preliminary or permanent) or law Subsidiaries that is in effect as of immediately prior to materially impact the Expiration Time which has the effect of prohibiting the consummation of the Offer or making the Merger illegal or otherwise prohibiting consummation of the Offer 2016 Conditional Deferred Payment or the Merger; (d) (i) the representations and warranties of the Company contained in Section 3.7(a) of the Agreement are not true and correct in all respects as of immediately prior to the Expiration Time, as though made at and as of such time, (ii) the representations and warranties of the Company contained in the last sentence of Section 3.2(a) of the Agreement, the third, fourth and last sentences of Section 3.2(b) of the Agreement and the first sentence of Section 3.2(c) of the Agreement are not true and correct in all but de minimis respects as of immediately prior to the Expiration Time, as though made at and as of such time (except to the extent any such representation or warranty expressly relates to an earlier date or period, in which case as of such date or period), (iii) the representations and warranties set forth in the first Annex I – Page 1 sentence of Sections 3.1(a), 3.4(a), 3.4(b)(i) and 3.20 of the Agreement are not true and correct in all material respects as of immediately prior to the Expiration Time, as though made at and as of such time (except to the extent any such representation or warranty expressly relates to an earlier date or period, in which case as of such date or period), or (iv) all other representations and warranties of the Company contained in the Agreement are not true and correct as of immediately prior to the Expiration Time, as though made at and as of such time (except to the extent any such representation or warranty expressly relates to an earlier date or period, in which case as of such date or period), except, in the case of this clause (iv), where the failure of such representations or warranties to be true and correct (without giving effect to any limitation as to “materiality” or “Company Material Adverse Effect” set forth in such representations and warranties) would not reasonably be expected to have a Company Material Adverse Effect; (e) the Company shall have failed to perform in all material respects its covenants and obligations required to be performed or complied with by it under the Agreement at or prior to the Expiration Time; (f) the Parent shall not have received a certificate, dated as of the date on which the Acceptance Time occurs, signed by an executive officer of the Company certifying that the conditions set forth in clauses (d) and (e) of this Annex I do not exist as of immediately prior to the Expiration Time; or (g) the Agreement shall have been validly terminated in accordance with Article VIII of the Agreement. Annex I – Page 2 THIS CONTINGENT VALUE RIGHTS AGREEMENT, dated as of [•] (this “Agreement”), is entered into by and among Biogen Inc., a Delaware corporation (the “Parent”), Apellis Pharmaceuticals, Inc., a Delaware corporation (together with any successor thereto, the “Company”), and [•], a [•], as Rights Agent2017 Conditional Deferred Payment.